From ba344843eb57bd93df8363ffdb384e6bf4c74fdd Mon Sep 17 00:00:00 2001
From: Min RK <benjaminrk@gmail.com>
Date: Tue, 1 Dec 2015 11:36:22 +0100
Subject: [PATCH] add SessionManager.close

allows explicit closing, rather than relying on implicit del,
which can run in the wrong thread.
---
 notebook/services/sessions/sessionmanager.py | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/notebook/services/sessions/sessionmanager.py b/notebook/services/sessions/sessionmanager.py
index ffd0cc28a..125940408 100644
--- a/notebook/services/sessions/sessionmanager.py
+++ b/notebook/services/sessions/sessionmanager.py
@@ -39,10 +39,16 @@ class SessionManager(LoggingConfigurable):
             self._connection = sqlite3.connect(':memory:')
             self._connection.row_factory = sqlite3.Row
         return self._connection
-        
+    
+    def close(self):
+        """Close the sqlite connection"""
+        if self._cursor is not None:
+            self._cursor.close()
+            self._cursor = None
+
     def __del__(self):
         """Close connection once SessionManager closes"""
-        self.cursor.close()
+        self.close()
 
     def session_exists(self, path):
         """Check to see if the session for a given notebook exists"""